The Chinese government just took over a port in Sri Lanka, the island nation off the shore of India, and you should probably be concerned.

Countries looking for development are increasingly looking east to China, rather than west to Europe and the United States. As America imposes tariffs on its allies and pulls out of international agreements such as the Trans-Pacific Partnership, China has been forthcoming with investment for infrastructure projects through its ambitious “One Belt, One Road” initiative.

Although Beijing’s buyout of a port in a country that most Americans likely couldn’t locate on a map may seem irrelevant, the strategic move highlights China’s broader goals of establishing regional dominance and control.

Sri Lanka recently had to hand over a port financed by Chinese investment along with 15,000 acres of land for 99-year lease to Beijing. On the surface, this gave China control over a failing port. On a deeper level, China gained a port close to India and leverage over the Sri Lankan government which remains deeply in debt to China.

Over the weekend, the prime minster of Sri Lanka announced that the country’s southern naval command will be moved to this port, now leased to China via a state-run firm. Signaling the reality of concerns about China’s desire to use the deep-water port for military purposes, the announcement reaffirmed that China would not be permitted to use the port for its own military purposes.

Despite this reassurance, however, Sri Lanka’s debt could pave the way for China to pressure the country to permit the very military use of land now held by China that it has repeatedly said that it would not.

China’s military actions in the region lend credibility to this fear. In 2014 Chinese submarines docked in Sri Lanka and China has been overtly working to build military capacity in the South China Sea.

The tale of the port should be a cautionary one. While Trump seems focused on trade deals and tariffs, U.S. attention to smaller, developing countries is waning and China is picking up the slack. Already, China has financed or helped finance at least 35 ports around the world and has included up to 68 countries representing 65 percent of the world’s population in the “One Belt, One Road” initiative.

The implications of China’s infrastructure investment are two-fold: not only does (1) China position itself to influence, through debt, the policy of foreign governments, but (2) China also gains control of strategic locations for military operations. While Beijing’s gains seem small so far, the overall ambitions evident in the scope of investment should be high on the list of U.S. concerns. If China takes over a few more ports and have some success in pressuring governments to allow military operations, China will soon pose more of a treat than just that of an economic rival.